

class Content_handler:
    """An instance of Content_handler handles data content by its MIME type."""
    def __init__(self, callback = None):
        """Creates a Content_handler instance. Content_handler handles data content by its MIME
        type. The optional callback is called when the embedded handler application started with
        the open method finishes.
        """
        pass
    
    def open(self, filename):
        """Opens the file filename (Unicode) in its handler application if one has been registered for the
        particular MIME type. The handler application is embedded in the caller's thread. The call to this
        function returns immediately. When the handler application finishes, the callback that was
        given to the Content_handler constructor is called.
        """
        pass
    
    def open_standalone(self, filename):
        """Opens the file filename (Unicode) in its handler application if one has been registered for the
        particular MIME type. The handler application is started in its own process. The call to this
        function returns immediately. Note that callback is not called for applications started with
        this method.
        """

    
    